#include 
#include 
using namespace std;

template
class Vector
{
public:
	typedef  T* Iterator;
	typedef const T* ConstIterator;

	Vector()  //空引數的建構函式
		:_start(NULL), _finish(NULL), _EndofStore(NULL)
	{}
	Vector(size_t n, T val)   //引數為n個value的構造
		:_start(new T[n]), _finish(_start), _EndofStore(_start+n)   
	{
		size_t i = 0;
		for (i = 0; i < n;i++)
		{
			_start[i] = val;
		}
		_finish = _start + n;    
	}

	Vector(const Vector & v)   //引數為Vector的拷貝構造
		:_start(NULL), _finish(NULL), _EndofStore(NULL)
	{
		size_t size = v.Size();
		if (size > 0)
		{
			Expand(size);
			for (size_t i = 0; i < size; i++)
			{
				_start[i] = v._start[i];
			}
			_finish = _start + size;	
		}
	}
	Vector(ConstIterator first, ConstIterator last)     //引數為迭代器區間的構造
		:_start(NULL), _finish(NULL), _EndofStore(NULL)
	{
		size_t size = first - last;
		if (size > 0)
		{
			Expand(size);
			for (size_t i = 0; i < size; i++)
			{
				_start[i] = first[i];
			}
			_finish = _start + size;
		}
	}

	~Vector()   //解構函式
	{
		Destroy();
	}

	bool Checkfull()
	{
		return _EndofStore >= _finish;
	}
	void Expand(size_t n)   //增容函式
	{
		assert(n > Capacity());
		T* tmp = new T[n];
		size_t size = Size();
		for (size_t i = 0; i < size; i++)    //擴容後拷貝原來資料
		{
			tmp[i] = _start[i];
		}

		delete[] _start;
		_start = tmp;
		_finish = _start + size;
		_EndofStore = _start + n;

	}
	void Destroy()       //銷燬Vector的函式
	{
		if (_start != NULL)
		{
			delete[] _start;
		}
		_start = _finish = _EndofStore = NULL;
	}

	size_t Size()const
	{
		return _finish - _start;
	}
	size_t Capacity()const
	{
		return _EndofStore - _start;
	}

	//迭代器的生成器
	Iterator Begin()
	{
		return _start;
	}
	Iterator End()
	{
		return _finish;
	}

	void CheckCapacity()
	{
		if (_finish == _EndofStore)
		{
			size_t newcapacity = Capacity() + 3;
			Expand(newcapacity);
		}
	}
	
	void Insert(Iterator pos, const T& x)  //隨機位置的插入函式，尾插頭插都靠他
	{
		size_t newpos = pos - _start;          
		//因為要調整空間，舊的pos在調整空間以後會失效，先記錄與_start的偏移量；在調整後的新空間能找到對應的新pos
		CheckCapacity();
		pos = _start + newpos;
		for (Iterator tmp = End(); tmp > pos; tmp--)
		{
			*tmp = *(tmp - 1);
		}
		*pos = x;
		_finish++;
	}

	void Erase(Iterator &pos)  //任意位置的刪除函式，尾刪頭刪都靠他
	{
		Iterator end = End();
		for  (; pos < (--end); pos++)
		{
			*pos = *(pos + 1);
		}
		_finish--;
	}

	void Pushback(const T& val)   //尾插
	{
		
		Insert(End(), val);
	}
	void Popback()   //尾刪
	{
		if (Size() != 0)
		{
			Iterator end= End();
			Erase( --end );
		}
	}
	void Pushfront(const T& val) //頭插
	{
		
		Insert(Begin() , val);
	}
	void Popfront()  //頭刪
	{
		if (Size() != 0)
		{
			Iterator start= Begin();
			Erase(start);
		}
	}

protected:
	Iterator _start;
	Iterator _finish;
	Iterator _EndofStore;
};